Insulated disposable cups for holding hot and cold beverages and other items have long been fabricated from inexpensive, light-weight materials such as expanded polystyrene. However, polystyrene is not biodegradable and therefore causes an environmental concern. Paper cups are also common, and are considered more environmentally sensitive, but are often undesirable since they readily transfer heat. A consumer may handle an uninsulated paper container with a napkin, another cup or other insulating sleeve. However, requiring a separate sleeve, cup or holder is expensive, cumbersome and may result in losing control of the container and unfortunate spillage of its contents.
FIG. 1 depicts a conventional insulated paper container 100 of the type substantially as described in U.S. Pat. No. 5,839,653. The container 100 has an upstanding wall 112 defining a volume 114 and is composed of a corrugated paperboard material having an inner paper layer 122, an insulating fluted layer 126 having vertically extending flutes 128, and an outer paper layer 124. However, when the upper edge of the upstanding wall 112 is rolled to form a lip 118, undesirable tearing or cracking 119 can result owing to the fiber orientation of the inner layer. Accordingly, this type of container does not consistently provide a desirable substitute for polystyrene containers and a need continues for environmentally friendly insulating containers.